MPLS virtual private network using dual network cores

ABSTRACT

A multi-protocol label switching system using multiple cores. In establishing a virtual private network in a MPLS system, more than one core is available. Paths are established over each core separately and weights are assigned to the two routes. Thus, the route which is preferred by manually configuring in advance will be chosen.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to a MPLS data networksystem and more particularly to a MPLS system where multiple cores canbe used for transporting data and different weights are assigned to thedifferent cores.

[0003] 2. Description of the Background Art

[0004] The present day worldwide web is composed of a number ofinterconnected data networks throughout the world. These data networksmay be of a number of different types, and were developed by differentproviders, based on different protocols. More recently, a MPLS(multi-protocol label switching) network has been designed which allowsvarious dissimilar data packets to be carried by the same network withthe addition of new labels, which are recognized by the MPLS system,regardless of the source of the original data. Thus, the MPLS networkmay be connected to dissimilar networks and carry packets of databetween them.

[0005] Entry points to a MPLS network are known as label edge routers.Such a router can accept traffic from different sources and thus may beconnected to different networks. Data packets are assigned labels asthey enter the network. These labels can provide a mechanism to grouprelated sets of the packets together and isolate one group of packetsfrom another. Thus, the packets are forwarded at layer 2, whicheliminates the need for layer 3 forwarding between nodes. Thissimplifies the forwarding process and results in high speed and highperformance.

[0006] Arrangements of MPLS networks are seen, for example, in U.S. Pat.Nos. 6,477,166 and 6,473,421.

[0007] The MPLS network can be used successfully by network serviceproviders, which provide a virtual private network service for theircustomers. That is, the data stream can be controlled without having tostop at every node along the path by setting up an end-to-endlabel-switching path. However, further improvements in these networksare possible, especially in a circumstance where a system is beingreplaced or upgraded in order to avoid any loss of service for thecustomer.

SUMMARY OF THE INVENTION

[0008] Accordingly, the present invention provides a method for usingmultiple network cores in a MPLS system.

[0009] Also, the present invention provides a system for using two ormore network cores to provide a virtual private network in a MPLSsystem.

[0010] The present invention further provides a system for providingdual network cores in a MPLS system where different weights are providedfor the different cores.

[0011] The present invention still further provides a method forweighting routes in dual network cores in a MPLS system.

[0012] The present invention further provides a MPLS virtual privatenetwork using dual network cores where the route through one core has adifferent weighting than the route through the other.

[0013] Briefly, this is achieved by providing a network having multiplecores within the network with addresses provided over both cores and aselection made based on a weight assigned to the different cores.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A more complete appreciation of the invention and many of theattendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawing,wherein:

[0015] The FIGURE is a diagram showing the system of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Referring now to the drawing, wherein the present system is shownas 10. This system includes two different network cores 12 and 14. Eachcore includes a series of routers. In network 12, routers 16, 18 and 20are shown. In network 14, routers 24, 26 and 28 are shown. Network 14also includes a route reflector 22.

[0017] The routers in network 12 are connected to each other as shown bylines 30, 32 and 34. Likewise, the routers in network 14 are connectedby lines 54, 56 and 58. While these are shown as individual lines, infact each of the lines may include a series of other routers along theway. Also, of course, each of the networks contains considerably morethan three routers.

[0018] In addition to the lines for carrying data between the routers,there are also connections to establish addresses between the variousrouters. Thus, in network 12 these are labeled as 36, 38 and 40. Whendata packets are passed from one router to another, a path is firstestablished by advertising addresses to other routers in the network.The path is then established before the data packet is passed. It isalso possible for data to be transferred between routers in differentnetworks. Thus, lines 42, 44 and 46 connect corresponding routers indifferent networks.

[0019] A route reflector 22 is also provided in network 14 to advertiseaddresses between the two different networks. Thus, address connections48, 50 and 52 are provided between this route reflector and the routersof network 12.

[0020] In operation, incoming data packets are connected to a label edgerouter in each core. Alternatively, one edge router may be used which isconnected to routers in both cores. When data is set to be transferred,a private virtual network is established by advertising addresses inboth cores. Two different paths are established with one path in eachcore. This arrangement allows a permanent virtual circuit to be formedin each network so that the data can be carried in either network.Weights are assigned to the different paths. If the weights are equal,the various packets will balance the load of the traffic over each core.However, normally one route will be favored over the other and assigneda higher weight. This is manually configured into the network. As aresult, packets are carried through one core rather than the other undernormal conditions. However, this arrangement provides the ability of theother core to also carry the data.

[0021] This arrangement can be especially useful in certaincircumstances. Thus, if the system is being upgraded to a different typeof network, it is possible to slowly bring data into the new network asit is being implemented. Thus, customers can be migrated from onenetwork core to another. It is also possible to use both cores in orderto increase the capacity of the system. It further provides the abilityto use different parallel carriers when necessary.

[0022] In operation, if the input is connected to router 16 whichoperates as the edge router, a first path is established in network 12by first advertising addresses over connections 36, 38 and 40 and a pathis established across the network using paths 30, 32 and 34. Of course,both the addressing and data paths have many more possible combinations.At the same time, a second path is configured through network 14 byadvertising addresses with route reflector 22 as indicated by 48, 50 and52. The route is then established using routers 24, 26 and 28 and datapaths 54, 56 and 58. However, once the two paths are established, aweight is given to each path, which is preset into the networksmanually. The weighting causes one path to be favored over the other.

[0023] It is also possible to utilize two cores merely as redundancyfeature to avoid problems with quality of service or to handle overloadsituations.

[0024] Numerous additional modification and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

1. A method for routing data packets through a network comprising:providing a plurality of cores in the network; connecting a data inputto each core by way of an edge router; determining a data path througheach core; weighting each path; and selecting one path for datatransmission.
 2. The method according to claim 1, wherein an edge routeris provided in each core.
 3. The method according to claim 1, whereinone edge router is connected to more than one core.
 4. The methodaccording to claim 1, wherein each path is determined by advertisingaddresses in the corresponding core.
 5. The method according to claim 1,wherein weights are set equally to load balance the cores.
 6. The methodaccording to claim 1, where weights are set manually in advance.
 7. AnMPLS network for transporting data, comprising: a plurality of cores; atleast one edge router for introducing data flow into each core; aplurality of routers in each core for establishing a data path in eachcore; wherein a weight for each path is manually inserted with one pathbeing selected based on said weight.
 8. A system according to claim 7,wherein the data path forms a virtual private network for a customer. 9.The system according to claim 7, wherein one edge router is provided foreach network.
 10. The system according to claim 7, wherein addresses areadvertised to establish a data path within a network.
 11. The systemaccording to claim 7, wherein distinct routing protocols are followed indifferent networks.